A vehicle such as an electric car which runs using an electric motor, and a hybrid car which runs using both an engine and an electric motor, is driven by an electric power which is supplied to the electric motor from a power supply mounted on the vehicle. In the hybrid car, for example, the electric motor and an inverter are connected to each other by an electric wire such as a motor cable. Moreover, the inverter is connected to an electric junction box (a junction box) which is provided in the power supply, and thus, the electric power is supplied from the power supply to the electric motor. On this occasion, the inverter and the electric junction box are connected to each other by way of a given connector member (a connector assembly).
As an example of the connector assembly as described above, there has been known the connector assembly having such a structure that a mounting hole is formed in a casing of the inverter or the electric junction box, a device-side terminal is provided in the casing, a wire-side terminal which is connected to a plurality of electric wires is held in a housing, and this housing is fitted to the mounting hole, thereby to connect the wire-side terminal to the device-side terminal (refer to Patent Literature 1). In the connector assembly having such a structure, a sealing member is attached to a groove part of the housing. In this manner, in a state where the housing is fitted to the mounting hole, a part between the groove part of the housing and an inner peripheral part of the mounting hole is sealed by the sealing member, and an interior of the casing is maintained in a liquid tight state.
In this case, the device-side terminal and the wire-side terminal are arranged laterally in a row, and according to such arrangement, both the housing and the mounting hole of the casing are formed in a laterally elongated elliptical shape (that is, a non-circular shape), as a whole. For this reason, also the sealing member which is attached to the housing is not formed in a circular shape, but formed in an elliptical shape. Therefore, when the sealing member is displaced with respect to the housing in a circumferential direction, there is an anxiety of such trouble that a part of the sealing member is lifted from the groove part of the housing or excessively expanded. In case where the sealing member is attached in this state, when the housing is fitted to the mounting hole, tight contact of the sealing member with respect to the groove part of the housing and the inner peripheral part of the mounting hole is not uniformly performed in the circumferential direction, and hence, deterioration of sealing performance is incurred.
For the purpose of eliminating the above described trouble, Patent Literature 1 discloses an example of the connector assembly having such a structure that the sealing member is provided with a lock part (a convex part), while the housing is provided with a regulating part (a concave part), and the lock part and the regulating part are engaged with each other, so that the sealing member is positioned with respect to the housing in the circumferential direction, and rotation of the sealing member in the circumferential direction with respect to the housing is also prevented.